Colorectal cancer (CRC) is the second most commonly diagnosed cancer and the third highest cause of mortality in Vietnamese and Asian Americans. CRC incidence is rising rapidly in Vietnamese Americans, but they have among the lowest rates of CRC screening (14%) and are more likely to be diagnosed with advanced stage disease, which is highly preventable. Over 85% of Vietnamese Americans in our region (PA, NJ and NYC) are foreign-born with limited English proficiency, have low SES, and live in economically disadvantaged neighborhoods. Many lack knowledge about CRC risks and screening benefits, and have limited access to culturally appropriate preventive care. Thus, a multilevel intervention is needed to address the multiple barriers to and determinants of CRC screening in this community. Vietnamese community organizations (VCOs) serve dynamic social functions and represent an important resource for addressing this critical health disparity priority by promoting CRC screening. This project builds on established partnerships and successful work of Center for Asian Health, Temple University with Vietnamese CBOs that address their critical health disparities. CBPR principles will be applied to engage 20 VCOs in all phases of planning, implementing, evaluating, and disseminating a culturally appropriate, theory- and evidence-based multilevel CRC intervention. The proposed intervention will be guided by Social Ecological Model, which addresses sociocultural, behavioral and environmental determinants and intervention strategies at individual, interpersonal, and community organizational levels. CDC's Clinical Preventive Services Guidelines for adults 50+ (CPS) recommend that cancer screenings and other preventive services should be promoted. The standard CPS will be provided to both intervention and control groups, and intervention group will receive CPS + multilevel CRC intervention. Specific Aim 1 is to test the hypothesis that CPS + multilevel CRC intervention will yield higher CRC screening rates compared to CPS control at 12-month follow up; Aim 2 is to examine whether CPS + multilevel CRC intervention (which includes CHW-led group education, automated and interactive text messaging and phone-based peer support) is more effective in changing screening determinants (e.g. KAB, self-efficacy, risk factors, lifestyles, social support, social norms, access barriers) than CPS control condition; and Aim 3 is to assess costs and cost-effectiveness of CPS + multilevel CRC intervention compared to CPS control condition in relation to CRC screening rates in order to inform future dissemination efforts. In sum, this project represents the first large-scale community-based randomized controlled trial of a multilevel, culturally-appropriate CBPR intervention to increase CRC screening among underserved Vietnamese. If effective, this innovative multilevel CRC intervention can be used as a model program that has potential generalizability and sustainability in Asian American and other underserved ethnic communities to impact preventive behaviors at population level.